Compressor



June 24, 1941.

'- 4A. TRAsK 2,246,868

June 24, 1941. fA. TRA'sK -coMPRFssoR Filed April 11', 1938 3 sheets-sheet 2 OOOO June 24,1941'. A. TRASK l 2,246,868

COMPRESSOR Filed April l1, 1938 3 Sheets-#Sheet 3 I 1I J I 2 *0,7 f5; ad l '64 227g# i. M ff,

Patented June 24, 1941 COMPRESSOR Allen Trask, Chicago,v Ill., assignor to Mills vNovelty Company, Chicago, Ill., a corporation of Illinois' Application April 11L 1,938, Serial No. 201,272

16 Claims.

former devices of this general nature, reliance has been placed upon the splash system in Which some portion, usually a small one, of the oil which is thrown off the crank shaft, etc., is expected to nd its way into the cylinders and upon the piston.

The present invention provides a greatly iml proved arrangement for lubricating the cylinders and pistons by providing for the positive direction of the oil which is pumped up to and escapes from the upper bearing of the crank shaft. down'- wardly along the rear end of the cylinder in the -top central region thereof so as to deposit such oil upon the top central portion of the skirt of the piston which is arranged to project beyond the rear end of the cylinder at he extremity of -its rearward stroke. l From this point the oil will flow on both sides of the skirt. and, following the same into the cylinder, will continue its travel down both sides of the wall of the cylinder.

A further object is to provide an arrangement tons may be accurately contr led at a predetermined rateof iiow, the excess ing returned directly to the oil reservoir. Y

. Another object of the invention is to provide, in

combination with such arrangement, an arrangement for directing a now of refrigerant vapor against the upper bearing of the compressorand around the interior of the housing 'thereof and in contact with the oil flowing from said bearing,

so as to cool the bearing, the shaft, the crank case, the cylinder heads, and the oil, and to carry the heat by forced convection from said partsto the housing.

Another object of the invention is to provide in a compressor of this type-embodying two cylinders and two pistons, in an integral cylinder block and crank case, an arrangement permitting ready removal of the pistons and connecting rods. To

this end, the invention provides an eccentricv member which is detachably mounted upon the crank shaft, the latter being spaced So that itmay be withdrawn from the eccentric member to allow the latter to. be moved to one side of the crankcase to a point remote from the cylinderso mewhat' as to expose the piston pin and allow its removal. Another object of Ithe invention is to provide an improved inlet valve of the self-unloading type mounted upon the head of a' piston. Insteadv of the normally dished valve disclosed in my prior patent, above identified, I employ a perfectly flat disc which is rigidly attached tothecentralregion ofthe piston head and arranged to coact with the valve seat formed in the periphery of said head. Means are provided for spacing the valve element a slight distance from the valve seat in its normal unstrained position, whereby the valve is normally unseated. The invention in this respect involves the discovery that fiat valve discs of resilient metal of proper thinness and diameter, will, under the influence,l of inertia during the compression stroke,r contract to a (lished shape seating against the valve seat. The invention in this respect aims to simplify and cheapen. the cost of construction of a valve arrangement of this type by eliminating the necessity of giving the valve a pre-dished shape and making it possible for all parts topbe machined perfectly flat.

Other objects of the invention will become apparent from the following detailed description of v the invention in connection with the accompany-v- 'in which the amount of oil delivered to the pisi Fig. 2v is a horizontal sectional view taken on.

the line 2-2 of F12. l.;

Fig. 3 is a horizontal sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a horizontal sectional view taken on the line 4--4 of Fig. land illustrating the removal of a piston pin;

Fig. 5 is an enlarged sectional view illustrating;

comprises an outer housing embodying an enlarged lower portion I0 to receive a compressor A and a reduced upper portion II to receive a motor B. The motor B embodies a stator I2, an

armature i3, and a shaft Il secured in the armature and projecting downwardly below the motor. 'The compressor A includes a crank c ase y I5 and a pair of cylinders I6, I'l, integrally formedA with and projecting fromopposite sides of the crank case l5. The compressor A is supported by means of an annular ange 59, formed integrally with the cylinders and crank case, projecting upwardly therefrom, and suitablysecured to the shell I2a of the motor B. Forming an upward projection of the top wall I8 of the crank case is an upper bearing I9 in which the projecting portion of the shaft I4 is journaled. The shaft is provided with an integral shoulder or flange 20 which bears against the upper end of the bearing I9 to carry the end portion of the shaft under its own weight and the weight of the armature I3.

Below a portion 2| of the shaft I4, which is journaled in the bearing I9, the shaft is reduced as at 22 to form a shoulder 23, against-which is received an eccentric member 24. The eccentric member 24 comprises an upper throw 25 and a lower throw 26, the former' receiving a bearing ring 21 of an upper connecting rod 28 and the latter receiving the bearing ring 21 of a"lower connecting rod 29.

Each cylinder I6, I1 has a cylinder bore 30 in which is received a piston 3l. Each piston 3l is connected to its respective rod 28, 29 by means of a piston pin 32.

The eccentric member 24 is securely held on the shaft portion 22 by means of a nut 33 mounted upon the shaft portion 22 and engaging a plate member `34 which projects beyond the periphery of the lower throw 26 to form a shoulder to support the ring 21 of the connecting rod 29.

The lower end of the shaft I4 is further reduced to form an en'd trunnion 35 which is journaled in a lower bearing 36 formed integrally with and projecting downwardly from the bottom of the crank case I5.

The bottom of the crank case'I5 is provided with an opening .or openings 31, which serve,

during the operation of the device, to allow oil to-be returned from the crank case I into the oil pan or reservoir 38 forming the bottom of the casing Il).

When it is desired to disassemble the device, access to the nut 33 may be had by extendingv a -proper tool through a door 60 (Fig. 4) in the crank case, normally closed by a closure plate 6I (Figs. 4 and 2), and as the nut 33 is unthreaded, the shaft I4 may be lifted upwardly, until it finally may belifted entirely out of the crank case. Thereupon, the eccentric member 24 may be moved to one side of the crank case, remote from one of the cylinders I6, I1, moving with it the connecting rods and the pistons, one piston being pushed farther into its cylinder and the other one being pulled out 'of its cylinder until the piston pin 32 of the latter is exposed sufficiently to be driven out through .thev opening 31. In order that this may be accomplished, openings 62 are provided inthe top wall I8 of the crank case, opposite the openings 31, and a toolmay be inserted through an opening 62, to engage the pin 32.

The lower bearing 36 extends into the body of oil in the oil reservoir 38, and the lower region of the crank shaft I4 is provided with helical oil pumping grooves 40 and 4I respectively for carrying theoil to the connecting rod bearings 21 and the upper bearing I9 respectively. Oil distributing passages 42, 43, and 44 are provided in the shaft for receiving and distributing the oil thus lifted by the spiral grooves.

Oil distributed to the bearing I9 will flow out between the top of the bearing and the shoulder 28, thence downwardly along the exterior of the bearing I9, to the top I8 of the crank case, where it will be collected. It is collected upon a plate 75 45, which is positioned upon the top wall I8 of the crank case and normally covers the opening 62 In the plate 45 are a pair of relatively small i openings 46, through which the oil collected upon the plate 45 will flow downwardly along the end walls of the cylinders I6, I1, respectively, to the points indicated by numerals 41, 48, respectively, Where the respective streams of oil will be delivered upon the piston 3|. The oil is collected and guided tothe openings 46 by means of a well 15fformed in the plate 45 by an upwardly .embossed bead 16, encircling the bearing I9 and extending to the openings 46.

The openings 46 being centered above cylinder 30, the oil streams will be delivered to the top central regions of the piston and will thence divide equally and flow along both sides of the piston, following the piston into the cylinder 30 and then owing downwardly along the sides of the cylinder.

In this manner any. desired amount ofthe oil escaping from the bearing I9 may be delivered to the pistons. The size of openings 46 determine the volume of oil delivered to the pistons.

A centrifugal Ventilating fan 49 embodies a top wall 59 formed with a central portion 50 which receives the shoulder 20 and is caught between said shoulder and the armature I3.- The fan has'an annular flange 5I which serves to direct the discharged refrigerant Vapor downwardly. It has conventional blades 52.

Between the fan and th'e top wall I8 of the .crank case is disposed a ring 53 the periphery of which substantially registerswith that of the fan with the exception of one sidewhich is flattened as at 54. -The ring 53 has an annular flange 55 extending aroundv its entire periphery and engaged against the plate member 45. Its central openingV forms the inlet, or eye of the fan.

Referring now to Fig. 3, it will be noted that the flange 55 extends beyond the flattened side of the crank case defined by a cover plate 6I ,thereby forming an inlet 60 through which vapor mayow into the space between themember 53 and the top of the crank case. From this space, .the yvapor flows (Fig. 2) through an opening 56, annularly shaped, between the member 53 and the bearing I9, into the center of the fan.

In leaving the fan, the vapor is discharged downwardly and tangentially through the space formed between the. fiat side 54 of the member 53 and the depending annular flange 5I of the fan.

The flattened side 54- is shaped to conform to the shape of the exhaust manifold 51 through Which the compressed fluid is led to the exhaust tube 58. This flow of air over the exhaust manifold helps to cool the same.

It may be noted that the vapor in traveling through the fan proceeds up one side of the' vcrank case, thence to the fan, and thence down the other side of the crank case. It may also be noted that the vapor-flow contacts the flow of oil from the top of the bearing I9 and through the opening 46. y

'I'hus the vapor first absorbs heat from the oil, then, as it travels into the' center-of the fan through the inlet thereof,` it cools the bearing I9.` After leaving the fan, it spirals downwardly outwardly past the cylinder heads cooling them, and thence into contact with the inner surface of the housing III, transferring its absorbed heat thereto. This heat is transferred by conduction vwhich gas may iiow from the piston through @the tothe heat dissipating varies Ilia and is then radiated into the atmosphere.\

The cooling of the bearing I9 is important in .view of the heat developed in the rotor i3 by the resistance characteristic of a motor of the type most suitable for the particularluse involved.

An improvement residing in the present invention is the arrangement of a crank case within an outerv housing, the lower part of which forms an oil reservoir, and the spacing of the delivery openings 31 in the crank case above the level -of the oil in the reservoir 38. In my prior patent above identified, the oil is delivered from the bottom of the crank case into the oil reservoir through a pair of tubes which extend down into the body of oil. I nd that the present arrangement is an improvement over that construction in that it eliminates a tendency for the oil to' be pumped up through the tubes into the crank case upon the compression stroke of the pistons.

'I'he crank case serves not only asa means for v collecting all of the oil-'that is thrown ofi` by the moving parts lof the compressor, but also serves to muille the noise of intake, compression, and exhaust, so as to make the unit very silent in operation. This muiiiing effect is secured by the combination of the crank case and the outer housing, and the arrangement of the crank case inside of the outer housing as shown. The openings 31, in addition to providing drain openings for the crank case, also provide breather vents for the crank case. p

The oil is delivered through the openings 31 by a pumping action caused by the movement of the pistons toward each other simultaneously.

'Ihe intake valve construction comprises a valve seat formed on the head ofthe piston and a exible metal disc valve, normally flat, secured to the head of the piston and adapted to move against the valve seat. 'I'he valve in its normally flat condition is indicated by the reference numeral 63 in Fig. 5 and is secured by means of a screw or other securing element 6I to a boss 65 inthe center vof the head of the piston. Between the boss 65 and the skirt 'of the piston are intake openings 66. The valve seat 61 is formed on the periphery of the cylinopenings 66. Thisspacing may be as small -as five-thousandths of an inch ons, piston o f f1"v diameter. In fact, it is necessary that the spacing be small in order that the invention may be successful. In case of even comparatively slight irregularities in tension or compression of the material of the valveA element, it will not curve with uniformity around its entire periphery and,

if the spacing is tooA great, it will assume a distorted shape in bowing, and will not seat properly.

By employing the arrangement where the spacing l is only slight, such as ve-thousandths vof an inch, however, I find that the valve will seat with suiiicient accuracy to produce efiicient results.

While it is possible to employ the above described feature in a compressor. in which the valve seats by the combined effect of inertia and iiuid resistance, in the preferred form of the invention, the thickness, diameter, and elasticity oi the valve disc, the region of attachment of the' disc to the piston'head, the normal'clearance between the valve disc and the valve seat, and the speed of reciprocation of the piston 3l are so related to one another that the inertia of the valve will overcome its elastic tendency to being unseated at that point of the compression `stroke of said piston at which no fluid tends to flow through said valve. In' other words, the arrangement is such that the valve will close solely by inertia without the assistance of the fluid which is being compressed. It is common practice in compress- Aors to employ an inlet valve that is held closed by tension. It is also old to employ an inlet '-valve that is normally unseated and to arrange the parts so that as the piston commences to compress the gas which has been drawn into the cyldrical wail of the piston, and is trunco-conical -inclination than that of the peripheral region of the valve 63 during curvature, so that. the re- 'gon of contact of the valve with the seat is a circular line or edge as illustrated at 69 in Fig.'`

1. Improved results may be secured by'plating the lower side of the valve element with a coatinder on the intake stroke, the pressure thus developed will aid in the closing of the valve. However, where this is the-case, the pressure thus de veloped will tend to cause a portion of the gas to escape before the valve closes.

The present invention aims to achieve vmaximum compressing efliciency by retaining all of the gas which has been drawn into the cylinder, the valve being arranged to close exactly at the point where all movement of the gas has stopped. Owing to the momentum, particularly in high? speed compressors, of the fluid as it ows into the compression chamber on the intake stroke, it will 'continue to flow into the compression chamber after the pressure difference between the chamber and the source of intake fluid has become equalized. Thus it is possible to attain momentarily in the compression-chamber a fluid pressure greater than that atits source. The present invention takes advantage of this momentum induced fluid pressure by closing the valve structure exactly at the .point where the fluid flow is at a standstill.

The foregoing detailed description has been given for clearness of understanding only and no l the prior art.

ing of soft metal such as lead or copper, as indicated at 10 in Fig. '1.

The valve element 63 is normally spaced away -from the valve seat, the high edge of which may be in the same plane with the face of the boss 65, l

so that the valve 6 3 in its normal unbowed condition is spaced above the valve seat 61, forming an opening around its entire periphery through I claim as my invention: p A

1. A hermetically sealed compressor. comprising, in combination, an outer housing, a motor shaft disposed on a vertical axis, a cylinder disposed on a horizontal axis, apiston in the cylinder including a skirt portion, a bearing projecting above the level of said cylinder, in which the shaft is journaled, meansfor feeding oil to said bearing, and means for directing the oil that een will flow by gravity across the end of the Wall of said cylinder into contact with the rear extrem- Vity of the skirt of said piston.

2'. A hermetically sealed compressor comprising, in combination, an outer housing, a motor shaft disposed on a, vertical axis', a cylinder disposed on a horizontal axis, a piston in the cylinder including a skirt portion, the rear extremity of the skirt of said piston being adapted' at the extremity of its rearward stroke to project from said cylinder, a. bearing projecting above the level of said cylinder, in which the shaft is journaled, means for feeding oil to said bearing, and means for directing the oil that escapes from said bearing to a point from which it will flow by gravity across the end of the wall of said cylinder, upon the projecting portion of the piston skirt at the top center thereof.

3. A hermetically sealed compressor comprising, in combination, an outer housing, a motor shaft disposed on a vertical axis, a cylinder disposed on a horizontal axis, a piston in the cylinder including a skirt portion, a bearing projecting above the level of said cylinder, in which the shaft is journaled, means for feeding oil-to said bearing, and a partition member between a point of discharge of. oil from said bearing and the means for directing the oil that escapes from said bearing to -a point*l from which lt will flow across the end of the wall of said cylinder into contact withthe rear extremity of the skirt of said piston, and means for creating a flow of yvapor in said housing in contact with such oil ow, whereby to cool the same, said means comprising a centrifugal fan carried by -said shaft, adapted to receive vapor from one side of said member, to cause such vapor to flow across said member to the eye of the fan, and to'thereafter discharge said vapor on the other side of the said member.

7. In' a hermetically sealed compressor, in combination, an outer housing, having a lubricant cylinder, surrounding said shaft and adapting' to collect the oil escaping from said bearing, said partition member having an opening located directly above the rear extremity of the Wall of said cylinder, the oil collected by said partition member being adapted to flow through said opening and across the said rear extremity of the cylinder wall, into'contact with the rear extremity of the skirt of said piston.

4. In a hermetically sealed compressor, in combination, an outer housing, a motor in the upper region thereof, said motor having a shaft projecting downwardly, a cylinder block including a cylinder, an upper bearing'projecting above the level of said cylinder, and a horizontal\member extending between a point of discharge of oil from said bearing said bearing and the cylinder and surrounding theshaft, said member being adapted to collect oil .escaping from said bearing, and an opening in said member through which oil thus collected is directed to ow downwardly across the rear extremity of the wall of said cylinder into contact with the rear extremity of said piston.

5. A hermetically sealed compressor comprising, in combination, an outer housing, a motor shaft disposed on a vertical axis, a cylinder dis'- posed on a horizontal axis, a piston in the cylinder including a skirt portion, a bearing projecting above the level of said cylinder, in which the shaft is journaled, means for feeding oil to said bearing, means for directing the oil that escapes from said bearing to a point from which it will flow by gravity across the end of the wall of said cylinder into contact with the rear extremity of the skirt of said piston, and means for creating a flow of vapor in said housing in contact with such oil iiow, whereby to cool the same.

6. A hermetically sealed compressor comprising, in combination, an outer housing, a motor shaft disposed on a vertical axis, a cylinder disposed on a horizontal axis,a piston iii the cylinder including askirt portion, a bearing projecting above the level 'of said cylinder, in which the shaft is journaled, a member extending between said bearing and said cylinder, means for feeding oil to said bearing, said member comprising reservoir formed in its lower region, a motor therein, a cylinder therein, a piston in said cylinder, an upper bearing in which said shaft is journaled, means for delivering oil from said reservoir vto said upper bearing, and means for directing the oil escaping from said bearing, to the rear extremity of the wall of said cylinder, whereby such oil -will iiow by gravity downwardly across the rear extremity4 of the wallvof said cylinder, into contact with said piston, said oil thence returning to said lubricant reservoir.

8. In a hermetically sealed compressor, in combination, an outer housing, a motor therein having a downwardly projecting shaft, a cylinder block'below -said motor, including a crank case and a cylinder projecting from said crank case,

Iand a cup-shaped centrifugal fan mounted on the shaft above the crank case and opening downwardly so as to discharge vapor from its peripheral region in a downwardly and outwardly spiralcharge vapor downwardly and outwardly from its peripheral region past said compressed-refrigerant passage, and into contact with the inner surface of said housing, and a bearing for said shaft projecting upwardly from -said crank case into said fan, oil from said bearing being discharged from the upper end thereof and adapted to flow downwardly along the exterior thereof, in contact with the flow of vapor entering said fan so as to be cooled thereby.

10. In a hermetically sealed compressor, in combination, an outer housing, a. motor therein having a downwardly projecting shaft, a vcylinder block below said motor, including a crank case and a cylinder projecting from said crank case, a passage for compressed refrigerant extending along one side of the crank case, a cup-shaped centrifugal fan mounted o'nthe shaft above the crank case and opening downwardly so as 'to discharge air downwardly and outwardly from its peripheral region, past said .compressedrefrigerant passage, and .a member cooperating with the upper wall of said crank case to form an air-inlet passage for said fan, extendingfrom the side of the crankcase opposite said lubricant passage, to the central region of-the fan, and

of the fan except in the region above said lu-bricant passage, where it is cut away to form ythe discharge opening of the fan. y

11. In a hermetically sealed compressor, an'

outer housing, a one-piececylinderblock therein comprising a central crank case and opposed lcylinders projecting therefrom, a motor, a motor shaft projecting through the crank case, a onepiece eccentric demountably attached to the ifshaft, pistons in the cylinders, connecting rods Cil , the head of the pistonin a plane spaced above l seat of trunco-conical shape, and a normally flat a disc valve element of thin', resilient metal, rthe -central region of which is rigidly secured to the head of the piston in a plane spaced above thev planeof the highest edge of said valve seat, the dimensions and flexibility of said valve element being so coordinated with respect to its normal spacing from the seatand the speed of reciprobeen drawn into the cylinder;

region of which is rigidly secured to the head of the piston in a plane spaced above the plane of the highest edgeof said valve seat,'the dimensions and flexibility of said valve element being so coordinated with respect to its normal spacing from the seat andthe speed of reclprocation, that said valve element will assume a dished shape and make closing contact with said seat solely under the eiect of inertia on the compression stroke of the piston and will lag on such closing until a maximum amountof fluid has -been drawn intothe cylinder. i

15. In a fluid compressor. in combination, a reciprocable piston having in its head a valve seat of trunco-conical shape, and a normally nat disc valve element of thin, resilient metal,-

the central regionof which is rigidly secured to the plane of the highest edge of said valve seat, the dimensions and flexibility of saidvalve element being so coordinated with respect to its l normal spacing from the seat and the speed of i such closing until -a maximum amount of fluid 13. In a fluid compressor, in combination, areciprocable piston having in its head a valve shape and making closing contact with vsaid seat under the effect of inertia. on the compression stroke ofthe piston and will lag on such closing v until a maximum amount of fluid has been drawn into the cylinder.

14. In a fluid compressor, in combination, a reciprocable piston having in its head a valve seat of annular shape, and a normally at disc valve element of thin, resilient metal, the central has been drawn into the cylinder, said valve seat being related to the valve element so as to conform to the inclination of the contacting portion of the latter. 1

16. In a fluid compressor, in combination, a

' reciprocable piston having in.its head a valve- `seat of annular shape, and a normally flat disc valve element of thin, resilient metal, the central region of which is rigidly secured to the head of the piston in a plane spaced above 'the plane l' of the highest edge of said valve seat, the dimensions and flexibility of said valve element being so coordinated with respect to its normal spacing from the seat and the speed of reclprocation, that said valve element will assume a dished shape and make closing contact with said seat stroke of the piston and will lag on such closing until a maximum amount of fluid has been drawn into the cylinder, said valve seat being in the form of a relatively sharp edge with relation to the contacting region of the valve element so as to make a circular line contact therewith.

man mask. 

